package com.thealgorithms.stacks; import static org.junit.jupiter.api.Assertions.assertEquals; import static org.junit.jupiter.api.Assertions.assertThrows; import java.util.stream.Stream; import org.junit.jupiter.params.ParameterizedTest; import org.junit.jupiter.params.provider.Arguments; import org.junit.jupiter.params.provider.MethodSource; class InfixToPostfixTest { @ParameterizedTest @MethodSource("provideValidExpressions") void testValidExpressions(String infix, String expectedPostfix) { assertEquals(expectedPostfix, InfixToPostfix.infix2PostFix(infix)); } private static Stream provideValidExpressions() { return Stream.of(Arguments.of("3+2", "32+"), Arguments.of("1+(2+3)", "123++"), Arguments.of("(3+4)*5-6", "34+5*6-")); } @ParameterizedTest @MethodSource("provideInvalidExpressions") void testInvalidExpressions(String infix, String expectedMessage) { Exception exception = assertThrows(Exception.class, () -> InfixToPostfix.infix2PostFix(infix)); assertEquals(expectedMessage, exception.getMessage()); } private static Stream provideInvalidExpressions() { return Stream.of(Arguments.of("((a+b)*c-d", "Invalid expression: unbalanced brackets.")); } }